Effects of Sour Tea (Hibiscus sabdariffa) on Lipid Profile and Lipoproteins in Patients with Type II Diabetes

Extraction Effects on Roselle Functionalities: Antioxidant, Antiglycation, and Antibacterial Capacities

This study investigated the effects of certain roselle (Hibiscus sabdariffa Linnaeus) extraction methods on various functional properties, including the antioxidant and antiglycation capacities and bacterial growth inhibition. Roselle anthocyanins were extracted using water and ethanol solvents at different temperatures and concentrations. The results revealed that the extraction rate increased with higher temperatures and ethanol concentrations (p < 0.05). Ethanol extracts exhibited higher total organic acid and total anthocyanin contents compared to water extracts, while water extracts showed higher total saccharide, total polyphenol, and total flavonoid contents (p < 0.05). Furthermore, the water extracts demonstrated superior Trolox equivalent antioxidant capacity (TEAC) values, while the ethanol extracts exhibited better 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, antiglycation capacity, and bacterial growth inhibition. A Pearson correlation analysis revealed strong associations between specific components and functional properties, such as a positive correlation between the total anthocyanin content and antiglycation capacity (R2 = 0.9862). A principal component analysis and agglomerative hierarchical clustering highlighted distinct clusters of water and ethanol extracts, indicating solvent-dependent variations in functional properties. This study assessed roselle extraction models for antioxidant, antiglycation, and antibacterial activities, which could be used for the development of functional alcoholic or non-alcoholic beverages.

Combining Different Natural Plant Extracts to Stabilize the Antioxidative Activity of Dragon's Blood

Dragon's blood () is a traditional Chinese medicine known for its wound hemostasis, blood circulation, and stasis properties. Recently, it has also been utilized in cosmetics, though its antioxidant capacity remains unclear. This study aims to stabilize the bioactivity of dragon's blood using various plant extracts. We evaluated single plant extracts and their combinations to identify the conditions that maintained the antioxidant capacity of dragon's blood the longest. Selected plants included Hibiscus sabdariffa, Clitoria ternatea, Hylocereus sp., Pandanus amaryllifolius, and Camellia sinensis. We used two sources of dragon's blood: Daemonorops draco and Dracaena cochinchinensis. Extraction conditions were optimized and antioxidant activity was assessed using the free radical scavenging ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH), total anthocyanin concentration (TAC), total polyphenol content (TPC), the free radical scavenging activity of ABTS, and a ferric reducing antioxidant power (FRAP) assay. The results showed that all plant extracts exhibited high antioxidant capacity. Clitoria ternatea had the highest DPPH scavenging ability at 93.81%, with the best combination being green tea and Daemonorops draco at 92.57%. Clitoria ternatea had the highest TPC at 9921 mg GAE/100 g, with the best combination (green tea and Dracaena cochinchinensis) at 10500 mg GAE/100 g. ABTS activity was highest for green tea at 98.3%, with the best combination (Clitoria ternatea and Daemonorops draco) at 93.29%. The FRAP assay showed that green tea had the highest electron-donating potential at 3.85 mg/mL, with the best combination (Daemonorops draco and Dracaena cochinchinensis) at 3.71 mg/mL. This study advances our understanding of the antioxidant properties of these plants and the traditional Chinese medicine dragon's blood, enhancing the efficacy of dragon's blood in skincare and cosmetics. Moreover, the application of these extracts could rejuvenate local agriculture, impacting the skincare, cosmetics, and sustainable agriculture sectors.

Therapeutic potentials of Hibiscus trionum: Antioxidant, anti-lipid peroxidative, hypoglycemic, and hepatoprotective effects in type 1 diabetic rats

Recent advances in diabetes treatment have primarily focused on insulin and hypoglycemic agents; however, there is growing interest in exploring herbal and synthetic alternatives. Numerous studies have highlighted the preventive effectiveness of regular plant consumption in managing chronic conditions, particularly diabetes. Hibiscus, a medicinal plant recognized in various cultures, is known for its diverse health benefits. This study investigated the impact of Hibiscus trionum on glycemic control and assessed its influence on glucose and insulin levels in diabetes-induced rats. The concentrations of antioxidant enzymes, particularly superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), were scrutinized across multiple body tissues (plasma, heart, muscle, liver, and kidney). The malondialdehyde (MDA) concentration, an indicator of lipid peroxidation, was examined in both plasma and tissue samples. Serum total cholesterol (TC), triglyceride (TG), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels were evaluated. Diabetic Group (D) exhibited a significant decrease in body weight, increased fluid and food consumption, elevated blood glucose levels, and increased antioxidant enzyme activity. Moreover, the diabetic group also showed increased levels of MDA, TC, TG, AST, and ALT, along with reduced insulin levels, compared to the control group. A substantial improvement in all parameters impaired by diabetes was observed following the application of Hibiscus trionum (HTT) in the Diabetes+HTT group. The antioxidative stress-reducing, lipid peroxidation-improving, and hepatoprotective potential of Hibiscus trionum in mitigating diabetes-induced oxidative stress is noteworthy. These findings indicate that HTT supplementation has valuable beneficial effects in protecting against the harmful impacts of diabetes.

A Holistic In Silico and In Vivo Approach to Exploring the Antidiabetic, Antioxidant, and Hepatoprotective Properties of Rose of Sharon

Diabetes mellitus (DM) is a significant global health burden that necessitates the exploration of effective and accessible therapeutic options. Phytotherapy has played a vital role in healthcare, with plant extracts being integral to traditional medicinal practices. The therapeutic potential of Hibiscus syriacus (Rose of Sharon), a plant with a rich ethnobotanical history, in the management of DM and its associated complications was investigated. In this study, the therapeutic potential of Hibiscus syriacus L. extract (HSE) against DM in streptozotocin (STZ)-induced diabetic rats was assessed, focusing on its effects on glucose regulation, antioxidative defense, and liver protection. The administration of the HSE extract substantially reduced hyperglycemia and increased insulin production, with concurrent improvements in body weight and hydration. The enhanced activity of antioxidant enzymes, such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), suggests reduced oxidative stress, which is further supported by molecular docking results with the 3GTV superoxide dismutase enzyme, showing a binding energy of -6.3 kcal/mol. A decrease in MDA levels also indicates a reduction in oxidative stress. Notably, HSE treatment led to decreased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and improved lipid profiles, indicating its hepatoprotective and lipid-modifying benefits. These findings support the inclusion of HSE as an adjunctive therapy in DM management strategies. This study promotes the consideration of Hibiscus syriacus L. therapeutic properties in global health contexts.

Lifestyle and Lipoprotein(a) Levels: Does a Specific Counseling Make Sense?

Lipoprotein(Lp)(a) is a variant of low-density lipoprotein (LDL), bound to apolipoprotein B100, whose levels are associated with a significant increase in the risk of atherosclerosis-related cardiovascular events, but also to aortic stenosis and atrial fibrillation. Since plasma levels of Lp(a) are commonly considered resistant to lifestyle changes, we critically reviewed the available evidence on the effect of weight loss, dietary supplements, and physical activity on this risk factor. In our review, we observed that relevant body weight loss, a relatively high intake of saturated fatty acids, the consumption of red wine, and intense physical exercise seems to be associated with significantly lower plasma Lp(a) levels. On the contrary, foods rich in trans-unsaturated fatty acids are associated with increased Lp(a) levels. With regard to dietary supplements, coenzyme Q10, L-Carnitine, and flaxseed exert a mild but significant lowering effect on plasma Lp(a).

Exploring the Health Benefits and Therapeutic Potential of Roselle (Hibiscus sabdariffa) in Human Studies: A Comprehensive Review

Hibiscus sabdariffa (HS), commonly known as Roselle, has a rich history of traditional uses and is recognized for its diverse pharmacological properties, including antihypertensive, anti-inflammatory, antimicrobial, and more. This comprehensive review synthesizes the existing literature on the health benefits associated with the consumption of HS or its ingredients. Key areas of focus include metabolic health, blood sugar, and lipid regulation, wherein studies have reported varying effects on parameters such as fasting blood glucose, insulin sensitivity, and lipid profiles. Furthermore, Roselle exhibits anti-inflammatory properties, as evidenced by its impact on inflammatory markers such as MCP-1 and TNF-α. Additionally, HS extracts have shown notable antibacterial efficacy against various strains, with a potential role in urinary tract infection management. Studies also suggest potential benefits for renal function, with improvements in markers such as blood urea nitrogen and creatinine levels. In this article, we aim to review the existing literature on the health benefits of HS.

Exploring the Impact of Nutrition on Non-Alcoholic Fatty Liver Disease Management: Unveiling the Roles of Various Foods, Food Components, and Compounds

There is a need to introduce standardized treatment options for non-alcoholic fatty liver disease (NAFLD) due to its global prevalence and the complications of this disease. Many studies have revealed that food-derived substances may be beneficial in dealing with this disease. Therefore, this review aims to evaluate the recently published studies on the food-derived treatment options for NAFLD. A comprehensive search of the PubMed database using keywords such as "NAFLD", "nutrition", "food", "derived", "therapy", and "guidelines" yielded 219 relevant papers for our analysis, published from 2004 to 2023. The results show the significant benefits of food-derived treatment in NAFLD therapy, including improvements in liver histology, hepatic fat amounts, anthropometric measures, lipid profile, and other metabolic measures. The availability of the substances discussed makes them a significant adjuvant in the treatment of this disease. The usefulness of Viusid as additional therapy to diet and physical activity should be emphasized due to improvements in liver histology; however, many other substances lead to a decrease in liver fat amounts including, e.g., berberine or omega-3 fatty acids. In addition, the synbiotic Protexin seems to be useful in terms of NAFLD treatment, especially because it is effective in both obese and lean subjects. Based on the latest research results, we suggest revising the therapeutic recommendations for patients suffering from NAFLD.

Hibiscus sabdariffa in Diabetes Prevention and Treatment—Does It Work? An Evidence-Based Review

Diabetes is currently a global health problem that is already reported as an epidemic. This metabolic disease, characterized by a disturbance in the carbohydrate, protein, and lipid metabolism, is often accompanied by disorders of several organs. Its treatment is expensive and often difficult to control. Therefore, it seems necessary to search for new drugs and solutions to facilitate therapy and reduce treatment costs. Herbal medicines are becoming more and more popular. Hibiscus sabdariffa (roselle) is a plant that grows wild in a tropical climate. It has been used in folk medicine for thousands of years. Thanks to the numerous active compounds, including polyphenols, polysaccharides, organic acids, or pectins, it is reported to exhibit hypoglycemic, antioxidant, hypotensive, and anti-lipidemic activities and numerous indirect effects that are related to them. The aim of this review was to update the knowledge about the therapeutic effects of roselle in diabetes and its comorbidities based on in vitro, animal, and human studies. After a careful analysis of the scientific literature, it can be stated that roselle is a promising product that can be used either on its own or as an addition to the conventional treatment regimens to prevent or treat diabetes and its accompanying diseases.

Physiological Effects and Human Health Benefits of Hibiscus sabdariffa: A Review of Clinical Trials

Hibiscus sabdariffa Linn. Malvaceae (HS) is characterized by its edible calyxes. The HS calyxes are widely used for cosmetic, food, and medicinal applications. According to ethnobotanical evidence, decoction, infusion, or maceration extracts from HS calyxes have been used in folk medicine to treat many ailments. Moreover, several in vitro and in vivo studies have demonstrated the pharmacological properties and potential human health benefits of HS consumption. On the other hand, the evaluation of the physiological effects and health benefits of HS in clinical studies is most challenging. Therefore, this narrative review summarizes and discusses the physiological effects and health benefits of HS calyxes reported in clinical trials. Preparations obtained from HS calyxes (extracts, infusions, decoction, teas, beverages, capsules, and pills) are used as non-pharmacological therapies to prevent/control diverse chronic non-communicable diseases. The most-reported HS health benefits are its antihypertensive, antidyslipidemic, hypoglycemic, body fat mass reduction, nephroprotective, antianemic, antioxidant, anti-inflammatory, and anti-xerostomic activities; these effects are associated with the phytochemicals found in HS. Moreover, no adverse effects were reported during the clinical trials. However, clinical studies exhibited some limitations; thus, further studies are required to validate the clinical efficacy of HS in large-scale studies with higher doses and a good experimental design

A systematic review and meta-analysis of the effects of Hibiscus sabdariffa on blood pressure and cardiometabolic markers

Context

Hibiscus sabdariffa (hibiscus) has been proposed to affect cardiovascular risk factors.

Objective

To review the evidence for the effectiveness of hibiscus in modulating cardiovascular disease risk markers, compared with pharmacologic, nutritional, or placebo treatments.

Data Sources

A systematic search of the Web of Science, Cochrane, Ovid (MEDLINE, Embase, AMED), and Scopus databases identified reports published up to June 2021 on randomized controlled trials using hibiscus as an intervention for lipid profiles, blood pressure (BP), and fasting plasma glucose levels in adult populations.

Data Extraction

Seventeen chronic trials were included. Quantitative data were examined using a random effects meta-analysis and meta-regression with trial sequential analysis to account for type I and type II errors.

Data Analysis

Hibiscus exerted stronger effects on systolic BP (−7.10 mmHg [95%CI, −13.00, −1.20]; I² = 95%; P = 0.02) than placebo, with the magnitude of reduction greatest in those with elevated BP at baseline. Hibiscus induced reductions to BP similar to that resulting from medication (systolic BP reduction, 2.13 mmHg [95%CI, −2.81, 7.06], I² = 91%, P = 0.40; diastolic BP reduction, 1.10 mmHg [95%CI, −1.55, 3.74], I² = 91%, P = 0.42). Hibiscus also significantly lowered levels of low-density lipoprotein compared with other teas and placebo (−6.76 mg/dL [95%CI, −13.45, −0.07]; I² = 64%; P = 0.05).

Conclusions

Regular consumption of hibiscus could confer reduced cardiovascular disease risk. More studies are warranted to establish an effective dose response and treatment duration.

Systematic Review Registration

PROSPERO registration no. CRD42020167295

Regulation of Apolipoprotein B by Natural Products and Nutraceuticals: A Comprehensive Review

Cardiovascular Disease (CVD) is the most important and the number one cause of mortality in both developing and industrialized nations. The co-morbidities associated with CVD are observed from infancy to old age. Apolipoprotein B100 (Apo B) is the primary apolipoprotein and structural protein of all major atherogenic particles derived from the liver including Very-Low- Density Lipoproteins (VLDL), Intermediate-density Lipoprotein (IDL), and Low-density Lipoprotein (LDL) particles. It has been suggested that measurement of the Apo B concentration is a superior and more reliable index for the prediction of CVD risk than is the measurement of LDL-C. Nutraceuticals and medicinal plants have attracted significant attention as it pertains to the treatment of non-communicable diseases, particularly CVD, diabetes mellitus, hypertension, and Nonalcoholic Fatty Liver Disease (NAFLD). The effect of nutraceuticals and herbal products on CVD, as well as some of its risk factors such as dyslipidemia, have been investigated previously. However, to the best of our knowledge, the effect of these natural products, including herbal supplements and functional foods (e.g. fruits and vegetables as either dry materials, or their extracts) on Apo B has not yet been investigated. Therefore, the primary objective of this paper was to review the effect of bioactive natural compounds on plasma Apo B concentrations. It is concluded that, in general, medicinal plants and nutraceuticals can be used as complementary medicine to reduce plasma Apo B levels in a safe, accessible, and inexpensive manner in an attempt to prevent and treat CVD.

The efficacy of sour tea (Hibiscus sabdariffa L.) on selected cardiovascular disease risk factors: A systematic review and meta-analysis of randomized clinical trials

This study sought to summarize clinical evidence of sour tea (Hibiscus sabdariffa L.) administration on cardiovascular disease risk factors. PubMed, Scopus, Institute for Scientific Information Web of Science, and Google Scholar were systematically searched from inception to June 2019 to identify randomized clinical trials, which assessed the effect of sour tea consumption on lipid profiles, fasting plasma glucose, and blood pressure in adult populations. Mean and standard deviation for each parameter were extracted to calculate effect size. Cochrane Collaboration tools were used to evaluate risk of bias assessment. A total of seven randomized clinical trials consisting 362 participants were included in the meta-analysis. Pooled effect size demonstrated that sour tea consumption significantly reduces fasting plasma glucose (-3.67 mg/dl, 95% confidence interval, CI [-7.07, -0.27]; I² = 37%), systolic blood pressure (-4.71 mmHg, 95% CI [-7.87, -1.55]; I² = 53%), and diastolic blood pressure (-4.08 mmHg, 95% CI [-6.48, -1.67]; I² = 14%). Although no significant effect was observed on triacylglycerol, total cholesterol, and high-density lipoprotein cholesterol following sour tea consumption, a trend toward a significant reduction was found in low-density lipoprotein cholesterol serum concentrations (p = 0.08). This systematic review and meta-analysis suggests that sour tea consumption could have beneficial effect in controlling glycemic status and blood pressure among adult population.

Stability and Quality of Anthocyanin in Purple Sweet Potato Extracts

Because of the high nutritional value of anthocyanin in purple sweet potatoes (TN57), the stability and quality of anthocyanin in purple sweet potatoes during and after the processing were investigated in this study. First of all, the extraction methods with different parameters, such as temperature, time, solid-liquid ratio, pH value, and solvent were employed to get better extraction efficiencies. After that, DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2′-azino-bis (3-ethylbenz thiazoline-6-sulphonic acid) were used to evaluate the anti-oxidation ability of the extracts. Lastly, the thermal degradation kinetics and photodegradation were used to obtain important degradation factors including the content of anthocyanin residue, degradation index (DI), color parameters, reaction rate (k), and chromatic aberration (ΔE). We found that the extraction condition as using 60% ethanol with 1% citric acid under 80 °C for 40 min was optimal for purple sweet potatoes, which obtained antioxidant capacity as 333 μM TE DPPH, 376 μM TE ABTS⁺, and 593.6 μM TE ferric ion reducing antioxidant power (FRAP). The results indicate that the most important parameter for the stability of anthocyanin in the purple sweet potato extract (PSPAE) was the pH value rather than temperature. In addition, there was no significant difference in chromatic aberration between the light and dark storage conditions under 37 °C. Thus, PSPAE has the potential to be developed as health foods and drinks rich in anthocyanin.

Formulation and characterization of an optimized functional beverage from hibiscus (Hibiscus sabdariffaL.) and green tea (Camellia sinensisL.)

Hibiscus sabdariffa and Camellia sinensis are traditionally consumed as beverages and are good sources of health-promoting phenolic compounds. The objective of this work was to use response surface methodology to develop an optimized functional beverage with high total phenolic content, antioxidant capacity, and acceptable for potential consumers. Optimum infusion conditions were 4.9 g of hibiscus calyces or C. sinensis leaves/100 ml of water at 26 ℃ for 291 min. These conditions yielded a total phenolic content of 14.80 ± 1.4 and 33.02 ± 0.34 mg gallic acid equivalents/100 ml for hibiscus and green tea, respectively. The optimized beverages were combined in a 7:3 (hibiscus:green tea, v/v) ratio; a consumer preference test showed that this combination had an acceptable taste according to untrained panelists. A chromatographic analysis showed that this formulation contained flavonoids, phenolic acids, and anthocyanins as its main components. Our data suggested that hibiscus and green tea phenolic compounds were efficiently extracted using near-ambient temperature water for prolonged times, contrary to routine methods (high temperature, short time). Our method also preserved antioxidant capacity, possibly by avoiding chemical changes/degradation due to high temperatures. This process can be used to produce organoleptically acceptable functional beverages that deliver a varied phenolic compound profile to the consumer.

Acute Effects of Hibiscus Sabdariffa Calyces on Postprandial Blood Pressure, Vascular Function, Blood Lipids, Biomarkers of Insulin Resistance and Inflammation in Humans

Background/Objectives: The acute impact of Hibiscus sabdariffa calyces (HSC) extract on postprandial vascular function and other cardiometabolic risk factors have not been studied previously. This study investigated the acute impact of HSC extract consumption on blood pressure (BP), vascular function and other cardiometabolic risk markers. Subjects/Methods: Twenty-five men with 1% to 10% cardiovascular disease (CVD) risk (determined by QRISK^®2) were randomised to consume either 250 mL of the aqueous extract of HSC or water with breakfast in a randomised, controlled, single-blinded, 2-meal cross-over study (ClinicalTrials.gov, NTC02165553) with a two weeks washout period between study days. BP was measured at baseline and hourly for 4 h. Flow mediated dilatation (FMD) of the branchial artery was measured at baseline, 2 and 4 h post intervention drink consumption. Results: Acute consumption of aqueous extract of HSC caused a significant increase in % FMD (p < 0.001), a non-significant decrease in systolic BP (SBP) and diastolic BP (DBP); non-significant increase in urinary and plasma nitric oxide (NOx) and reduced response of serum glucose, plasma insulin, serum triacylglycerol and C-reactive protein (CRP) levels; significant (p = 0.026) improvement in the area under systemic antioxidant response curve (0 to 2 h); no significant changes in arterial stiffness following the acute consumption of the extract of HSC. Gallic acid, 4-O-methylgallic acid, 3-O-methylgallic acid and hippuric acid reached a maximum plasma concentration at 1 to 2 h post consumption of the extract of HSC. Conclusion: The extract of HSC improved postprandial vascular function and may be a useful dietary strategy to reduce endothelial dysfunction and CVD risk, although this requires confirmation.

Roselle Anthocyanins: Antioxidant Properties and Stability to Heat and pH

Roselle is rich in anthocyanins and is traditionally used to prepare a bright red beverage by decoction. However, heat treatment and different pH environments are often encountered during food processing, and these factors are often detrimental to anthocyanins. Therefore, it is very important to understand the influence of pH and heat treatment on anthocyanins for the application of roselle. This study determined the antioxidant properties of roselle extract, explored changes in the color and anthocyanin content in different pH environments, and evaluated the thermal stability of roselle anthocyanins using kinetic equations. The results showed that the roselle extract is rich in anthocyanins and has good antioxidant capacity (DPPH IC50 = 4.06 mg/mL, ABTS IC50 = 3.7 mg/mL). The anthocyanins themselves exhibited a certain degree of heat resistance and good color stability in an acidic environment. In contrast, they degraded very quickly and exhibited significant changes in color in a low-acid environment. The activation energy (Ea) ranges of the anthocyanins in the acidic and low-acid environments were quite different at 55.8–95.7 and 31.4–74.9 kJ/mol, respectively. Thus, it can be concluded that roselle anthocyanins are susceptible to heat treatment in a low-acid environment, affecting their quality and appearance; however, they can serve as a good source of functional ingredients and color in an acidic environment.

The Effects of Boswellia serrata Gum Resin on the Blood Glucose and Lipid Profile of Diabetic Patients: A Double-Blind Randomized Placebo-Controlled Clinical Trial

Regarding preclinical evidence for antidiabetic effects of Boswellia serrata, we evaluated antihyperglycemic and lipid-lowering effects of Boswellia serrata gum resin in type 2 diabetic patients. Fifty-six diabetic patients were randomly allocated to 2 groups to receive 250 mg of the Boswellia serrata gum resin or placebo twice daily for 8 weeks in addition to their routine antidiabetic treatments. Although there was a considerable reduction after the intervention in the field of fasting blood sugar, glycosylated hemoglobin, and triglyceride in the Boswellia serrata gum resin group, no significant difference was observed in all outcome measures between the 2 groups at the end of the study. The current study showed that 8 weeks of complementary use of Boswellia serrata gum resin with a daily dose of 500 mg had no better glucose and lipid-lowering effect than placebo in diabetic patients.

Efficacy of standardized extract of Hibiscus sabdariffa L. (Malvaceae) in improving iron status of adults in malaria endemic area: A randomized controlled trial

ETHNOPHARMACOLOGICAL RELEVANCE

Indigenous community of Mkuranga district have been using aqueous extract of H. sabdariffa L. for treating anemia. However, there have been neither safety nor efficacy studies to validate this medicinal product in anemia.

AIM

The purpose of this study was to establish efficacy and safety of standardized aqueous extract of H. sabdariffa L. in anemic adults.

MATERIALS AND METHODS

This was a randomized controlled clinical trial in which 130 adults' men and women aged 18-50 years were involved after meeting the inclusion criteria. Initially, standardized aqueous extract of H. sabdariffa L. was prepared using optimized extraction parameters. Stratified randomization was used to randomize participants into four fixed dose groups. The first group received oral dose of 1000ml while the 2nd group was randomized to receive 1500ml orally. The last two groups were given a dose of 2000ml of extract and 200mg ferrous sulphate tablet respectively. Primary endpoint was the actual change of iron status indicators at the end of 30 days follow up period as compared to those recorded at baseline. Adverse effects were assessed at every 10th day scheduled visit. In all arms, HB and hematopoietic parameters were measured using HemoCue hemoglobinometer® (HemoCue, Ängelholm, Sweden) and hematology analyzer® respectively at the trial site. Follow up was done for 30 days. A total of 82 participants were included for analysis.

RESULTS

A standardized aqueous extract of H. sabdariffa L. did not improve iron status in anemic adults in malaria endemic region (P>0.005). However, there was evidence to support the safety of the extract for human consumptions as herbal supplement. Iron and organic acids contents of H. sabdariffa L. extract showed the potential of improving hematopoietic parameters. Studies with bigger sample size are therefore needed to establish the efficacy of the extract when concurrently used with malaria chemoprophylaxis in malaria endemic areas.

A Systematic Review and Meta-Analysis of the Effects of Flavanol-Containing Tea, Cocoa and Apple Products on Body Composition and Blood Lipids: Exploring the Factors Responsible for Variability in Their Efficacy

Several randomized controlled trials (RCTs) and meta-analyses support the benefits of flavanols on cardiometabolic health, but the factors affecting variability in the responses to these compounds have not been properly assessed. The objectives of this meta-analysis were to systematically collect the RCTs-based-evidence of the effects of flavanol-containing tea, cocoa and apple products on selected biomarkers of cardiometabolic risk and to explore the influence of various factors on the variability in the responses to the consumption of these products. A total of 120 RCTs were selected. Despite a high heterogeneity, the intake of the flavanol-containing products was associated using a random model with changes (reported as standardized difference in means (SDM)) in body mass index (−0.15, p < 0.001), waist circumference (−0.29, p < 0.001), total-cholesterol (−0.21, p < 0.001), LDL-cholesterol (−0.23, p < 0.001), and triacylglycerides (−0.11, p = 0.027), and with an increase of HDL-cholesterol (0.15, p = 0.005). Through subgroup analyses, we showed the influence of baseline-BMI, sex, source/form of administration, medication and country of investigation on some of the outcome measures and suggest that flavanols may be more effective in specific subgroups such as those with a BMI ≥ 25.0 kg/m², non-medicated individuals or by specifically using tea products. This meta-analysis provides the first robust evidence of the effects induced by the consumption of flavanol-containing tea, cocoa and apple products on weight and lipid biomarkers and shows the influence of various factors that can affect their bioefficacy in humans. Of note, some of these effects are quantitatively comparable to those produced by drugs, life-style changes or other natural products. Further, RCTs in well-characterized populations are required to fully comprehend the factors affecting inter-individual responses to flavanol and thereby improve flavanols efficacy in the prevention of cardiometabolic disorders.

Dietary Strategies and Novel Pharmaceutical Approaches Targeting Serum ApoA-I Metabolism: A Systematic Overview

The incidence of CHD is still increasing, which underscores the need for new preventive and therapeutic approaches to decrease CHD risk. In this respect, increasing apoA-I concentrations may be a promising approach, especially through increasing apoA-I synthesis. This review first provides insight into current knowledge on apoA-I production, clearance, and degradation, followed by a systematic review of dietary and novel pharmacological approaches to target apoA-I metabolism. For this, a systematic search was performed to identify randomized controlled intervention studies that examined effects of whole foods and (non)nutrients on apoA-I metabolism. In addition, novel pharmacological approaches were searched for, which were specifically developed to target apoA-I metabolism. We conclude that both dietary components and pharmacological approaches can be used to increase apoA-I concentrations or functionality. For the dietary components in particular, more knowledge about the underlying mechanisms is necessary, as increasing apoA-I per se does not necessarily translate into a reduced CHD risk.

Hibiscus sabdariffa (Roselle) Extracts and Wine: Phytochemical Profile, Physicochemical Properties, and Carbohydrase Inhibition

Three varieties of Hibiscus sabdariffa were analyzed for their phytochemical content and inhibitory potential on carbohydrate-digesting enzymes as a basis for selecting a variety for wine production. The dark red variety was chosen as it was highest in phenolic content and an aqueous extract partially inhibited α-glucosidase (maltase), with delphinidin 3-O-sambubioside, cyanidin 3-O-sambubioside, and 3-O-caffeoylquinic acid accounting for 65% of this activity. None of the varieties significantly inhibited α-amylase. Regarding Hibiscus sabdariffa wine, the effect of fermentation temperature (20 and 30 °C) on the physicochemical, phytochemical, and aroma composition was monitored over 40 days. The main change in phytochemical composition observed was the hydrolysis of 3-O-caffeolquinic acid and the concomitant increase of caffeic acid irrespective of fermentation temperature. Wine fermented at 20 °C was slightly more active for α-glucosidase inhibition with more fruity aromas (ethyl octanoate), but there were more flowery notes (2-phenylethanol) at 30 °C.

Evaluation of the effects of roselle (Hibiscus sabdariffa L.) on oxidative stress and serum levels of lipids, insulin and hs-CRP in adult patients with metabolic syndrome: a double-blind placebo-controlled clinical trial

BACKGROUND

Roselle (Hibiscus sabdariffa L.) is a plant with antihyperlipidemic and antihypertensive effects. This study aimed to evaluate the effects of roselle calyces on the serum levels of lipids and insulin, inflammation, and oxidative stress in patients with metabolic syndrome (MetS).

METHODS

Forty adult patients with MetS were randomly assigned to receive either 500 mg of H. sabdariffa calyx powder or placebo once daily for 4 weeks. Systolic and diastolic blood pressures (SBP and DBP) and BMI (body mass index) as well as fasting serum levels of glucose (FPG; fasting plasma glucose), insulin, lipoproteins, triglycerides (TG), high-sensitivity C-reactive protein (hs-CRP), and malondialdehyde (MDA) were determined pre- and post-intervention and compared.

RESULTS

H. sabdariffa significantly reduced serum TG (p=0.044) and SBP (p=0.049) compared to placebo. All other variables were not significantly affected by the interventions.

CONCLUSIONS

Daily consumption of 500 mg of H. sabdariffa L. calyx powder can decrease SBP and serum TG in MetS patients.

Hibiscus sabdariffa calyx palliates insulin resistance, hyperglycemia, dyslipidemia and oxidative rout in fructose-induced metabolic syndrome rats

BACKGROUND

The effect of Hibiscus sabdariffa calyx extract was evaluated in high-fructose-induced metabolic syndrome rats. Insulin resistance, hyperglycemia, dyslipidemia and oxidative rout were induced in rats using high-fructose diet. High-fructose diet-fed rats were administered 100 and 200 mg kg(-1) body weight of H. sabdariffa extract for 3 weeks, starting from week 7 of high-fructose diet treatment.

RESULTS

High-fructose diet significantly (P < 0.05) increased the serum levels of blood glucose, insulin, total cholesterol (TC), triacylglycerol (TAG), low-density lipoprotein cholesterol (LDLc) and very-low-density lipoprotein cholesterol (VLDLc), with a concomitant reduction in high-density lipoprotein cholesterol (HDLc). These alterations were significantly ameliorated by the extract. High-fructose diet-mediated decreases in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-red) and glucose 6-phosphate dehydrogenase (Glc 6-PD) were significantly (P < 0.05) attenuated. Altered levels of reduced glutathione (GSH) and glutathione disulfide (GSSG) were significantly (P < 0.05) restored to normal. High-fructose diet-mediated increases in the concentrations of malondialdehyde, conjugated dienes, lipid hydroperoxides, protein carbonyl and percentage fragmented DNA were significantly (P < 0.05) lowered by the Hibiscus extract.

CONCLUSION

Overall, aqueous extract of H. sabdariffa palliates insulin resistance, hyperglycemia, dyslipidemia and oxidative rout in high-fructose-induced metabolic syndrome rats.

Diabetes mellitus and its management with medicinal plants: A perspective based on Iranian research

ETHNOPHARMACOLOGICAL RELEVANCE

Complementary and alternative medicine has been increasingly used to treat chronic illnesses, such as diabetes mellitus. However, various limitations in terms of their application and efficacies exist. Furthermore, there is still much to be done to discover the right herbal medicine for diabetes.

AIM OF THE STUDY

This paper aims to evaluate previous herbal studies on the management of diabetes mellitus, to address their strengths and weaknesses and propose a general framework for future studies.

APPROACH AND METHODS

Data sources such as PubMed, ScienceDirect, Scopus, SpringerLink, and Wiley were searched, limited to Iran, using 36 search terms such as herbal, traditional, medicine, and phytopharmacy in combination with diabetes and related complications. Reviewed articles were evaluated regarding the use of botanical nomenclature and included information on (1) identity of plants and plant parts used, (2) the processing procedure, and (3) the extraction process. The main outcomes were extracted and then surveyed in terms of the efficacies of herbs in the management of diabetes mellitus. Then a comparative study was performed between Iranian and non-Iranian studies with respect to herbs best studied in Iran.

RESULTS

Of the 82 herbs studied in Iran, only six herbs were endemic and 19 were studied in detail. Although most of the reviewed herbs were found to decrease the level of blood glucose (BG) and/or glycated hemoglobin (HbA1C) in both Iranian and non-Iranian studies, information on their pharmacological mechanisms is scarce. However, the level of HbA1C was measured in a limited number of clinical trials or animal studies. Available information on both short- and long-term use of studied herbs on diabetes related complications and functions of involved organs as well as comorbid depression and/or simultaneous changes in lifestyle is also insufficient. Furthermore, little or no information on their phytochemical, toxicological, and herb-drug interaction properties is available. It is worth noting that the efficacy of the reviewed herbs has been studied scarcely in both humans and animals regarding both Iranian and non-Iranian studies. A significant number of reviewed articles failed to cite the scientific name of herbs and include information on the processing procedure and the extraction process.

CONCLUSIONS

Treatment of diabetes mellitus as a multifactorial disease using herbal medicines requires a comprehensive approach. In order to discover the right herbal medicine for the management of diabetes many other important factors than the levels of BG, HbA1C and insulin should be considered. According to our criteria, all the reviewed herbs suffered from inadequate investigation in human, animal and in vitro models in this respect, whereas they are worth investigating further. However, more research on endemic plants and the traditional history of herbal medicine is warranted. In our opinion, the pharmacological, toxicological, and phytochemical information should be obtained before clinical trials. Furthermore, information such as botanical scientific nomenclature, side effects, and toxicity will improve the quality and validity of publications in herbal research. In particular, designing a database covering all valid information about herbs and/or diseases will decrease unnecessary costs and increase the efficiency of research.

Effect of sour tea (Lipicom) pill versus captopril on the treatment of hypertension

Introduction: Herbal medicines are traditionally prescribed to manage blood pressure.

Objectives: We aimed to evaluate effect of sour tea pill containing the herb’s extract versus captopril on the treatment of hypertension.

Patients and Methods: In our crossover clinical trial 20 patients were enrolled in the study and advised for life style modification then the participants were randomly divided into 2 groups. Sour tea pills was prescribed at a dose of 500 mg and captopril at a dose of 12.5 mg twice daily. In order to improve precision and final measurement, ambulatory blood pressure monitoring (ABPM) was performed both prior and after measuring the hypertension in 2 successive visits. After 6 weeks of therapy, the methods changed and 6 weeks later ABPM was performed three times (baseline, at end of the 6th and 12th week). The 2 groups were merged together before data analysis.

Results: Of the 20 patients, 13 (65%) were male and 7 (35%) were female. No significant difference of sex, age, and job was detected between 2 groups (P ≥ 0.05). Mean decreasing in systolic blood pressure was 7.75 ± 8.3 and 13.3 ± 16.1 mm Hg in the captopril and sour tea groups, respectively. Also, mean decline in diastolic blood pressure decreases was 2.15 ± 4.14 and 5.8 ± 7.8 mm Hg for captopril and sour tea groups, respectively. No side effect was observed in the sour tea pill group in the study.

Conclusion: According to the effect of sour tea pill on decreasing blood pressure, without giving priority over captopril, sour tea pill containing the herb’s extract can be prescribed as an adjuvant therapy for lowering the prescribed dosage of captopril.

Permeability Study of Polyphenols Derived from a Phenolic-Enriched Hibiscus sabdariffa Extract by UHPLC-ESI-UHR-Qq-TOF-MS

Previous findings on the capacity of Hibiscus sabdariffa (HS) polyphenols to ameliorate metabolic disturbances justify the necessity of studies oriented to find the potential metabolites responsible for such an effect. The present study examined the intestinal epithelial membrane permeability of polyphenols present in a phenolic-enriched Hibiscus sabdariffa extract (PEHS), free and encapsulated, using the Caco-2 cell line. Additionally, selected polyphenols (quercetin, quercetin-3-glucoside, quercetin-3-glucuronide, and N-feruloyltyramine) were also studied in the same absorption model. The powerful analytical platform used ultra-high-performance liquid chromatography coupled with ultra-high-resolution quadrupole time-of-flight mass spectrometry (UHPLC-ESI-UHR-Qq-TOF-MS), and enabled the characterization of seven new compounds in PEHS. In the permeation study, only a few compounds were able to cross the cell monolayer and the permeability was lower when the extract was in an encapsulated form. Pure compounds showed a moderate absorption in all cases. Nevertheless, these preliminary results may need further research to understand the complete absorption mechanism of Hibiscus polyphenols.

Evaluation of the Potential Nephroprotective and Antimicrobial Effect of Camellia sinensis Leaves versus Hibiscus sabdariffa (In Vivo and In Vitro Studies)

Green tea and hibiscus are widely consumed as traditional beverages in Yemen and some regional countries. They are relatively cheap and the belief is that they improve health state and cure many diseases. The aim of this study was to evaluate the potential protective and antibacterial activity of these two famous plants in vitro through measuring their antibacterial activity and in vivo through measuring nonenzymatic kidney markers dysfunction after induction of nephrotoxicity by gentamicin. Gram positive bacteria like MRSA (methicillin resistant Staphylococcus aureus) were isolated from hospitalized patients' different sources (pus and wound) and Gram negative bacteria including E. coli and P. aeruginosa were used in vitro study. In addition, the efficacy of these plants was assessed in vivo through measuring nonenzymatic kidney markers including S. creatinine and S. urea. Green tea was shown antimicrobial activity against MRSA with inhibition zone 19.67 ± 0.33 mm and MIC 1.25 ± 0.00 mg/mL compared with standard reference (vancomycin) 18.00 ± 0.00 mg/mL. Hibiscus did not exhibit a similar effect. Both Hibiscus- and green tea-treated groups had nephroprotective effects as they reduced the elevation in nonenzymatic kidney markers. We conclude that green tea has dual effects: antimicrobial and nephroprotective.

Iranian medicinal plants for diabetes mellitus: a systematic review

In the Iranian traditional medicine a significant usage of herbs is promoted for their anti-diabetic activity. The aim of this review to assess the efficacy of glucose lowering effects of medicinal plants cultivated in Iran. An electronic literature search of MEDLINE, Science Direct, EMBASE, Scopus, Web of Science, Cochrane Library Database, Ebsco and Google Scholar from database inception conducted up to May 2012. A total of 85 studies (18 humans and 67 animals) examining 62 plants were reviewed. The quality of Randomized Controlled Trials (RCTs) assessed by using the Jadad scale. Among the RCTs studies, the best results in glycemic control was found in Aloe vera, Citrullus colocynthus, Plantago ovata, Silybum marianum, Rheum ribes and Urtica dioica. The majority of plants that have been studied for antidiabetic activity showed promising results. However, efficacy and safety of the most plants used in the treatment of diabetes are not sufficient.

The effect of green tea and sour tea on blood pressure of patients with type 2 diabetes: a randomized clinical trial

INTRODUCTION

The use of herbal medicines including different types of tea is among the different strategies for preventing and controlling the side-effects of diabetes. The aim of the present study was to compare the effect of sour tea and green tea on mildly hypertensive patients with diabetes.

METHODS

The present study was a randomized clinical trial in which 100 mildly hypertensive patients with diabetes were randomly assigned into sour tea group (ST) and green tea group (GT). They were instructed to drink sour tea and green tea infusion, respectively, three times a day 2 hr after each meal for 4 weeks. The participants' blood pressure was measured at days 1, 15, and at the end of study.

RESULTS

The systolic pressure of both groups statistically decreased at the end of the study; it decreased from 123.1 ± 15.5 to 116.8 ± 16.3 mmHg in the ST and from 119.4 ± 15.1 to 114.8 ± 15.9 mmHg in the GT. The diastolic pressure of both groups statistically decreased by the end of the study; it decreased from 79.4 ± 11.1 to 74.5 ± 9.3 mmHg in the ST and from 78.9 ± 8.3 to 75.3 ± 7.7 mmHg in the GT. The therapeutic effectiveness of tea drinking by the end of intervention was 43.5% in the ST and 39.6% in the GT compared to the beginning.

CONCLUSIONS

The present study revealed that mildly hypertensive type 2 diabetic individuals who drink three glasses of green or sour tea daily for 4 weeks show significant decreased systolic and diastolic blood pressures.

Trends in publication of evidence-based Traditional Iranian medicine in endocrinology and metabolic disorders

Traditional Iranian medicine (TIM) is a main part of complementary and alternative medicine (CAM). The popularity and use of alternative therapies are increasing due to adverse effects and ineffectiveness of pharmacologic treatments in some cases. Herbal medicine is one of the methods of traditional therapy that plays a key role in the treatment of various diseases specifically in diabetes mellitus, hyperlipidemia and obesity that are growing rapidly in the world. In this article, trends of scientific publications of Iranian medicine in endocrinology and metabolic disorders have been investigated. Our data show that the numbers of related researches have uptrend from 2000 till now. These data are valuable to pharmaceutical companies to get the idea to invest and produce effective drugs.

Effects of Hibiscus sabdariffa L. on serum lipids: a systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Prevention of cardiovascular disease by modifying its major risk factors, including serum cholesterol levels, is an important strategy. Hibiscus sabdariffa L. has been promoted for reducing cholesterol levels, but its reported impact on cholesterol levels has been inconsistent. The study aimed to assess systematically the evidence and quality of current research on the effect of Hibiscus sabdariffa L. on blood lipids and its adverse effects.

MATERIALS AND METHODS

Electronic databases were searched up to June 2013 for relevant randomised controlled trials (RCTs). Journals and conference proceedings were also searched. The quality of the selected trials was assessed using the Cochrane Risk of Bias Assessment Tool. The efficacy results of similar studies were pooled if they used the same comparator. Outcomes examined were levels of total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol and triglycerides.

RESULTS

Six studies involving 474 subjects met our inclusion criteria. These studies varied in terms of the types of interventions, comparators used, and duration of trials. Overall, Hibiscus sabdariffa L. did not produce any significant effect on any of the outcomes examined, when compared with placebo, black tea or diet. With short-term use it is well tolerated.

CONCLUSIONS

The available evidence from RCTs does not support the efficacy of Hibiscus sabdariffa L. in lowering serum lipids. Further rigorously designed trials with larger sample sizes are warranted to confirm the effects of HS on serum lipids.

Insulin secretion enhancing activity of roselle calyx extract in normal and streptozotocin-induced diabetic rats

Background and Objective:

Our recent study revealed the antihyperglycemic activity of an ethanolic extract of roselle calyxes (Hibiscus sabdariffa) in diabetic rats. The present study had, therefore, an objective to investigate the mechanism underlying this activity.

Materials and Methods:

Male Sprague Dawley rats were induced to be diabetes by intraperitoneal injection of 45 mg/kg streptozotocin (STZ). Normal rats as well as diabetic rats were administered with the ethanolic extract of H. sabdariffa calyxes (HS-EE) at 0.1 and 1.0 g/kg/day, respectively, for 6 weeks. Then, blood glucose and insulin levels, at basal and glucose-stimulated secretions, were measured. The pancreas was dissected to examine histologically.

Results:

HS-EE 1.0 g/kg/day significantly decreased the blood glucose level by 38 ± 12% in diabetic rats but not in normal rats. In normal rats, treatment with 1.0 g/kg HS-EE increased the basal insulin level significantly as compared with control normal rats (1.28 ± 0.25 and 0.55 ± 0.05 ng/ml, respectively). Interestingly, diabetic rats treated with 1.0 g/kg HS-EE also showed a significant increase in basal insulin level as compared with the control diabetic rats (0.30 ± 0.05 and 0.15 ± 0.01 ng/ml, respectively). Concerning microscopic histological examination, HS-EE 1.0 g/kg significantly increased the number of islets of Langerhans in both normal rats (1.2 ± 0.1 and 2.0 ± 0.1 islet number/10 low-power fields (LPF) for control and HS-EE treated group, respectively) and diabetic rats (1.0 ± 0.3 and 3.9 ± 0.6 islet number/10 LPF for control and HS-EE treated group, respectively).

Conclusion:

The antidiabetic activity of HS-EE may be partially mediated via the stimulating effect on insulin secretion.

Hibiscus sabdariffa L. in the treatment of hypertension and hyperlipidemia: a comprehensive review of animal and human studies

The effectiveness of Hibiscus sabdariffa L. (HS) in the treatment of risk factors associated with cardiovascular disease is assessed in this review by taking a comprehensive approach to interpreting the randomized clinical trial (RCT) results in the context of the available ethnomedical, phytochemical, pharmacological, and safety and toxicity information. HS decoctions and infusions of calyxes, and on occasion leaves, are used in at least 10 countries worldwide in the treatment of hypertension and hyperlipidemia with no reported adverse events or side effects. HS extracts have a low degree of toxicity with a LD50 ranging from 2,000 to over 5,000mg/kg/day. There is no evidence of hepatic or renal toxicity as the result of HS extract consumption, except for possible adverse hepatic effects at high doses. There is evidence that HS acts as a diuretic, however in most cases the extract did not significantly influence electrolyte levels. Animal studies have consistently shown that consumption of HS extract reduces blood pressure in a dose dependent manner. In RCTs, the daily consumption of a tea or extract produced from HS calyxes significantly lowered systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults with pre to moderate essential hypertension and type 2 diabetes. In addition, HS tea was as effective at lowering blood pressure as the commonly used blood pressure medication Captropril, but less effective than Lisinopril. Total cholesterol, low-density lipoprotein cholesterol (LDL-C), and triglycerides were lowered in the majority of normolipidemic, hyperlipidemic, and diabetic animal models, whereas high-density lipoprotein cholesterol (HDL-C) was generally not affected by the consumption of HS extract. Over half of the RCTs showed that daily consumption of HS tea or extracts had favorable influence on lipid profiles including reduced total cholesterol, LDL-C, triglycerides, as well as increased HDL-C. Anthocyanins found in abundance in HS calyxes are generally considered the phytochemicals responsible for the antihypertensive and hypocholesterolemic effects, however evidence has also been provided for the role of polyphenols and hibiscus acid. A number of potential mechanisms have been proposed to explain the hypotensive and anticholesterol effects, but the most common explanation is the antioxidant effects of the anthocyanins inhibition of LDL-C oxidation, which impedes atherosclerosis, an important cardiovascular risk factor. This comprehensive body of evidence suggests that extracts of HS are promising as a treatment of hypertension and hyperlipidemia, however more high quality animal and human studies informed by actual therapeutic practices are needed to provide recommendations for use that have the potential for widespread public health benefit.

Synergism of plant-derived polyphenols in adipogenesis: perspectives and implications

Dietary polyphenols may exert their pharmacological effect via synergistic interactions with multiple targets. Putative effects of polyphenols in the management of obesity should be primarily evaluated in adipose tissue and consequently in well-documented cell model. We used Hibiscus sabdariffa (HS), a widely recognised medicinal plant, as a source of polyphenols with a number of salutary effects previously reported. We present here the full characterisation of bioactive components of HS aqueous extracts and document their effects in a model of adipogenesis from 3T3-L1 cells and in hypertrophic and insulin-resistant adipocytes. Aqueous extracts were up to 100 times more efficient in inhibiting triglyceride accumulation when devoid of fibre and polysaccharides. Significant differences were also observed in reactive oxygen species generation and adipokine secretion. We also found that, when polyphenols were fractionated and isolated, the benefits of the whole extract were greater than the sum of its parts, which indicated a previously unnoticed synergism. In conclusion, polyphenols have interactive and complementary effects, which suggest a possible application in the management of complex diseases and efforts to isolate individual components might be irrelevant for clinical medicine and/or human nutrition.

Hibiscus sabdariffa polyphenolic extract inhibits hyperglycemia, hyperlipidemia, and glycation-oxidative stress while improving insulin resistance

H. sabdariffa polyphenolic extract (HPE) was demonstrated to inhibit high glucose-stimulated cellular changes. In this study, we analyzed the composition of HPE and used a type 2 diabetic rat model to test its protective effect. At least 18 phenolic compounds were found in HPE. Treatment with HPE reduced hyperglycemia and hyperinsulinemia, especially at the dose of 200 mg/kg. HPE decreased serum triacylglycerol, cholesterol, and the ratio of low density lipoprotein/high density lipoprotein (LDL/HDL). Diabetes promoted plasma advanced glycation end product (AGE) formation and lipid peroxidation, while HPE significantly reduced these elevations. Immunohistological observation revealed that HPE inhibited the expression of connective tissue growth factor (CTGF) and receptor of AGE (RAGE), which was increased in type 2 diabetic aortic regions. Furthermore, HPE recovered the weight loss found in type 2 diabetic rats. In conclusion, we demonstrated the anti-insulin resistance properties of HPE and its effect on hypoglycemia, hypolipidemia, and antioxidation. HPE has the potential to be an adjuvant for diabetic therapy.